Quarantining from other bird species..

I'm quarantining my 7 new buttons of course, but what are the chances that they could possibly have a disease that could be given to ducks and parrots (like budgies, tiels, lovebirds). Because I want to know if I should be careful with little things like touching the doorknob to the bathroom when going to wash up after touching them, or changing my clothes even though my clothes didnt even touch them and things like that. They're only 3-4 weeks old and seemed to have been kept in clean conditions. The person didn't have any other birds either but she said she's only had them about a week... I think she mentioned something about her aunt giving them to her and she said her aunt has ducks. so maybe for two weeks of their life they were around other birds, but I'm not entirely sure about that.

I have chickens, button quail, and coturnix quails. I dont wash my hands when feeding them all. They are separated from eachother (atleast now they are...the buttons were in with teh coturnix at one point). None are sick. *Some* *say* they can transfer illnesses, but i say....yeah...if they're sick to begin with, not a healthy quail to a healthy chicken. If that's the case i'd be doomed. LOL